1576
|
Kato Y, Kenne K. Inhibition of cell-cell communication by commercial chlorinated paraffins in rat liver epithelial IAR 20 cells. PHARMACOLOGY & TOXICOLOGY 1996; 79:23-8. [PMID: 8841092 DOI: 10.1111/j.1600-0773.1996.tb00236.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The effects of six commercial chlorinated paraffins of different carbon chains length and chlorine content (Cereclor 50LV [C50LV], Hüls 60 [H60], Cereclor S45 [CS45], Cereclor S52 [CS52], Cereclor 42 [C42] and Cereclor 48 [C48] on cell communication have been investigated in the scrape-loading/dye-transfer assay in IAR 20 rat liver epithelial cells, as well as the effects of these compounds on connexin 43 (cx 43), the main gap junction protein in this cell line. The results clearly demonstrated that at non-cytotoxic concentrations C50LV, H60, CS45 and CS52 completely inhibited the cell communication within 1 hr. The short carbon chain length chlorinated paraffins (C50LV and H60) were inhibiting the cell communication at lower concentration than the intermediate carbon chain length chlorinated paraffins (CS45 and CS52). Almost complete inhibition of the cell communication was maintained for at least 24 hrs of H60 exposure. Immunoblots of IAR 20 cell extracts after H60-exposure showed a decreased phosphorylation of cx 43 after 1, 4 and 24 hrs of treatment. The phosphorylation pattern of cx 43 prepared from H60- or CS52-exposed cells was different from that prepared from 12-O-tetradecanoylphobol-13-acetate (TPA)-exposed cells after 1 hr treatment. The results show that the short and intermediate, but not the long carbon chain length chlorinated paraffins, are potent inhibitors of gap junction intercellular communication. Thus, our findings suggest that these compounds may act as tumour promoters.
Collapse
|
1577
|
Kato Y, Masumiya H, Agata N, Tanaka H, Shigenobu K. Developmental changes in action potential and membrane currents in fetal, neonatal and adult guinea-pig ventricular myocytes. J Mol Cell Cardiol 1996; 28:1515-22. [PMID: 8841938 DOI: 10.1006/jmcc.1996.0141] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Developmental changes in electrophysiological properties were investigated in enzymatically isolated ventricular cardiomyocytes from fetal (45-55 days after conception), neonatal (1-5 days after birth) and adult (45-60 days after birth) guinea-pigs. Action potentials were elicited at 1 Hz in current-clamp mode, and membrane currents were measured using whole cell voltage clamp method. Action potential durations at 50% and 90% repolarization decreased between fetal and neonatal periods and increased between neonatal and adult periods, while there was no substantial age-related change in resting membrane potential and action potential overshoot. Because cell membrane capacitance increased with age, indicating a developmental increase in cell size, current density was normalized to membrane capacitance for each cell. The L-type calcium current (lCaL) density at 0 and + 10 mV was significantly smaller in fetal and neonatal cells than in adult ones, although the voltage dependence and inactivation kinetics were similar among the three age groups. The delayed rectifier K+ current (lK) density at 0 and + 30 mV was significantly smaller in fetal cells than in neonatal and adult ones. No significant difference in the inward rectifier K+ current (lK1) density was observed among the three age groups. Thus, the electrophysiological properties of the guinea-pig ventricular myocytes were demonstrated to change during pre- and postnatal development. The observed changes in action potential duration could be explained by changes in the balance between lK and lCaL.
Collapse
|
1578
|
Hisa T, Taniguchi S, Kakudo K, Ichihashi M, Takashima T, Kato Y, Hayakawa R, Takigawa M. Establishment of an in vitro cell derived from human angiosarcoma. Bull Cancer 1996; 83:589-91. [PMID: 8868948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We have succeeded in the establishment of a human endothelial cell line derived from a human angiosarcoma. These cells grew as monolayers with a "cobble stone" morphology. The cells produced endothelin and showed Weibel-Palade bodies in their cytoplasm. These findings show that the cells have specific differenciated functions, and might be useful for both fundamental endothelial cell biology and biological investigation of angiosarcoma.
Collapse
|
1579
|
Osoegawa K, Okano S, Kato Y, Nishimura Y, Soeda E. A 19-kb CpG island associated with single-minded gene 2 in Down syndrome chromosomal region. DNA Res 1996; 3:175-9. [PMID: 8905236 DOI: 10.1093/dnares/3.3.175] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
To help in isolating the genes involved in Down syndrome, we sought CpG islands in 4 Mb cosmid/PAC contigs spanning most of the 21q.22.2 band using seven rare cutting enzymes. A striking feature was observed upstream of hSIM2 where at least 41 rare-cutting sites were clustered within a 20-kb region. To investigate the structure of the cluster, a cosmid containing hSIM2 was submitted to shotgun sequencing. Sequence analysis revealed that the cluster was a long CpG island extending 19, 128 nucleotides which includes in the first and second exons of hSIM2. Taken together with our observation in which the CpG islands were concentrated within 1.2 Mb around hSIM2, we propose that this region functions as an R-band, and the cluster provides a unique element for marking of DNA for the spatial and temporal expression of the hSIM2 locus.
Collapse
|
1580
|
Frébort I, Pec P, Luhová L, Toyama H, Matsushita K, Hirota S, Kitagawa T, Ueno T, Asano Y, Kato Y, Adachi O. Two amine oxidases from Aspergillus niger AKU 3302 contain topa quinone as the cofactor: unusual cofactor link to the glutamyl residue occurs only at one of the enzymes. BIOCHIMICA ET BIOPHYSICA ACTA 1996; 1295:59-72. [PMID: 8679675 DOI: 10.1016/0167-4838(96)00014-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Amine oxidases (EC 1.4.3.6) from Aspergillus niger, AO-I (2 x 75 kDa) and AO-II (80 kDa), were examined to determine the cofactor structure. Inactivated with p-nitrophenylhydrazine, they showed absorption and fluorescence spectra similar to those published for other copper amine oxidases and to topa hydantoin p-nitrophenylhydrazone. After digestion by thermolysin and pronase, cofactor peptides were purified by HPLC and sequenced. For thermolytic peptides, a typical topa consensus sequence, Asn-X-Glu-Tyr, was obtained for AO-II, although in case of AO-I it overlapped with Val-Val-Ile-Glu-Pro-Tyr-Gly. For pronase peptides of AO-I, only the latter sequence was obtained. NMR and mass spectroscopy confirmed the residue X as topa p-nitrophenylhydrazone in AO-II and revealed the presence of a residue Z attached to the Glu in the peptide Val-Val-Ile-Glu(Z)-Pro of AO-I. This residue was separated from the peptide by hydrolysis and identified as a product derived from topa quinone. The data, together with amino-acid sequence of AO-I, confer strong evidence for topa quinone as the cofactor, bound in the typical consensus sequence. Raman spectra of the p-nitrophenylhydrazone derivative of AO-I and its pronase peptide showed essentially the same peaks matching to a model compound for topa p-nitrophenylhydrazone. However, there may exist an unusual ester link between the topa-404 and Glu-145 in the native enzyme.
Collapse
|
1581
|
Ogawa M, Maeda K, Chung YS, Onoda N, Kato Y, Nakata B, Sowa M. [Correlation between expression of RB protein and prognosis of gastric cancer]. Gan To Kagaku Ryoho 1996; 23 Suppl 2:148-50. [PMID: 8678558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
In this study, the expression of retinoblastoma (RB) protein was investigated immunohistochemically in 94 patients with gastric cancer. Overexpression of RB was detected in 48 tumors (51.1%). There was no significant association among the expression of RB, histologic type, lymph node metastasis, and liver metastasis. However, a significant difference was noted with respect to depth of invasion and peritoneal metastases. Among 94 patients, peritoneal metastases were observed in 11 patients. RB expression was detected in only two of these cases with peritoneal metastases, which was significantly less than those without peritoneal metastases. In relation to prognosis, patients with RB-positive tumors had a significantly better prognosis than those with RB-negative tumors. In conclusion, this study suggested that expression of RB has a prognostic value in gastric cancer.
Collapse
|
1582
|
Takahashi M, Kato Y, Miyakawa G, Kurosu A, Kamiyama S. Allele detection and population study in Japanese using two STR loci (CYP19 and HUMTH01). Int J Legal Med 1996; 108:321-2. [PMID: 8793642 DOI: 10.1007/bf02432129] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Allele fragments at two polymorphic short tandem repeat (STR) loci, CYP19 and HUMTH01, were simultaneously amplified in a sample of 200 unrelated Japanese individuals living in the Kanto area, including Tokyo. After electrophoresis in PAG, the new alleles 7, 10, 11, 12, and 13 were detected at the CYP19 locus in Japanese. HUMTH01 allele frequencies in Japanese differed greatly from those reported for Caucasians and Asians living in the US. The polymorphism information content (PIC) in Japanese was calculated as 0.46 for CYP19 and 0.66 for HUMTH01. The power of discrimination (PD) was 0.7 for CYP19 and 0.86 for HUMTH01, and the combined PD was calculated as 0.96. No significant deviations from Hardy-Weinberg equilibrium could be observed for these systems.
Collapse
|
1583
|
Sasaki M, Kawabata M, Asaji A, Takakuwa H, Ohta H, Kobayashi K, Matsui O, Kato Y. [Long-term effect of transcatheter arterial embolization therapy for renal angiomyolipoma]. NIHON JINZO GAKKAI SHI 1996; 38:273-7. [PMID: 8752970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We report a case of a 21-year-old man with a right renal angiomyolipoma who has been observed for 20 months after successful treatment with selective transcatheter arterial embolization (TAE). In May 1993, he was transferred to our hospital for the treatment of an abdominal mass. Examination revealed a solid and fat-containing right renal tumor on computed tomography (CT) and magnetic resonance imaging (MRI), hypervascular staining with multiple peripheral microaneurysms on renal angiogram, indicating an angiomyolipoma (AML). He did not have any signs of tuberous sclerosis. Because he complained of abdominal pain and the tumor was 9 cm in diameter, TAE of the tumor using polyvinyl alcohol foam was performed to prevent life-threatening hemorrhage. Renal angiogram after TAE demonstrated a complete shut-down of blood supply to the tumor and CT scan, 6 and 20 months after TAE, demonstrated a decrease in size to 4.5 cm in diameter, showing a favorable long-term effect of treatment. He has been symptom-free for 20 months. TAE appears to be a safe and effective treatment for AML, preventing tumor growth and thus possibly hemorrhage or rupture of the tumor over the long -term.
Collapse
|
1584
|
Noguchi N, Sakai H, Kato Y, Tsuchiya J, Yamamoto Y, Niki E, Horikoshi H, Kodama T. Inhibition of oxidation of low density lipoprotein by troglitazone. Atherosclerosis 1996; 123:227-34. [PMID: 8782853 DOI: 10.1016/0021-9150(96)05811-x] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The effect of a new oral hypoglycemic agent troglitazone, (+/-)-5-[4-(6-hydroxy-2,5,7,8-tetramethylchroman-2-yl-methoxy)benz yl]-2,4-thiazolidinedione as an antioxidant against the free radical-mediated oxidation of low density lipoprotein (LDL) was studied. The oxidation of LDL gives cholesteryl ester hydroperoxide and phosphatidylcholine hydroperoxide as major primary products. Troglitazone incorporated exogenously into LDL inhibited the oxidations of LDL induced by either aqueous or lipophilic peroxyl radicals and suppressed the formation of lipid hydroperoxides efficiently. Ascorbic acid added into the aqueous phase spared both endogenous alpha-tocopherol and troglitazone in LDL. It was also found by absorption spectroscopic and electron spin resonance (ESR) studies that troglitazone reacted rapidly with a galvinoxyl radical to give a chromanoxyl radical which gives the same ESR spectrum as alpha-tocopherol. This ESR spectrum disappeared rapidly when ascorbic acid was added into the system. These results show that troglitazone acts as a potent antioxidant and protects LDL from oxidative modification.
Collapse
|
1585
|
Sano H, Kato Y, Zhou J, Watanabe S, Okuma I, Hayakawa M, Kanno T. New jet irrigation bipolar system. Neurosurgery 1996; 38:1251-3. [PMID: 8727160 DOI: 10.1097/00006123-199606000-00044] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Irrigation bipolar systems are particularly useful for the washout of hematomas in subarachnoid hemorrhage during the acute stage of surgery and for preventing adherence of tissue to the bipolar tips during coagulation. These systems have become essential tools, and numerous improvements have been made to them. First, regarding the flow volume, both the interval of droplets and the size of individual water droplets can be adjusted. Second, this system is equipped with two major functions. The first is a preirrigation function, in which a small amount of irrigation water flows before operation of the bipolar coagulation. This wets the bipolar tips, eliminating any heat remaining from the previous use. Another function is postirrigation; after the coagulation has stopped, continuous irrigation is quickly provided to achieve a standby state by cooling down the tissue and the tips of the bipolar forceps. By using both of these functions, mild coagulation without adherence of burned tissue and clots to the bipolar forceps and minimization of residual heat during frequent use can be achieved. This article describes the new jet irrigation bipolar system and the use of an actual system that combines jet irrigation functions with the new cooling functions.
Collapse
|
1586
|
Nakata B, Chung YS, Kato Y, Ogawa M, Ogawa Y, Inui A, Maeda K, Sawada T, Sowa M. Clinical significance of serum CYFRA 21-1 in gastric cancer. Br J Cancer 1996; 73:1529-32. [PMID: 8664124 PMCID: PMC2074562 DOI: 10.1038/bjc.1996.288] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
We studied the clinical significance of the soluble cytokeratin 19 fragment detected with monoclonal antibody CYFRA 21-1 in the sera of patients with histologically proven gastric cancer. Sera of 110 patients with gastric cancer were analysed for CYFRA 21-1 levels by a two-step sandwich enzyme immunoassay. There were no significant differences between CYFRA 21-1 levels and the histotype, depth of invasion or vessel invasion. However, CYFRA 21-1 was significantly higher in the presence of peritoneal metastases, liver metastases and extensive nodal involvement. When the positive cut-off value was defined as 5 ng ml-1, the CYFRA 21-1 in the stage IV and recurrent cases was 55.6% and 66.7%, respectively, which was as high as carcinoembryonic antigen (CEA) and greater than carbohydrate antigen 19-9 (CA 19-9). The positivities in stage I/II and III were zero and 5.9%, respectively, and false-positive rate in 76 patients with benign gastrointestinal disorders was 2.6%. There appeared to be no correlation between CYFRA 21-1 and CEA or CA 19-9. The patients with above 5 n ml-1 of CYFRA 21-1 had a significantly poorer prognosis. Multivariate analysis indicated that CYFRA 21-1 was an independent prognostic factor, while CEA and CA 19-9 failed to be of prognostic value. In conclusion, CYFRA 21-1 is a reliable tumour marker for gastic cancer in predicting very advanced cases, recurrence of the disease and overall poor prognosis.
Collapse
|
1587
|
Rubio CA, Kumagai J, Nakamura K, Yanagisawa A, Kato Y. Leuchtenberger bodies in flat adenomas of the colorectal mucosa: a comparison between Japanese and Swedish patients. Jpn J Cancer Res 1996; 87:618-22. [PMID: 8766526 PMCID: PMC5921132 DOI: 10.1111/j.1349-7006.1996.tb00268.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The dysplastic epithelium of flat colorectal adenomas was found to contain DNA inclusion granules, known as Leuchtenberger bodies (LB). Hematoxylin and eosin-stained sections of 263 colorectal flat neoplastic lesions (i.e., flat adenomas, and flat adenocarcinomas) collected in Japan and Sweden were scrutinized for the presence of such intraepithelial inclusions. LB were recorded in 87.1% of the 263 flat colorectal neoplastic lesions. The frequency of flat colorectal lesions having LB was similar in Japan (160 of 178 or 89.8%) to that in Sweden (69 of 85 flat lesions or 81.2%), suggesting that the occurrence of LB may not be influenced by race or environment. Direct immunoperoxidase detection of nuclear DNA fragmentation and transmission electron microscopy studies indicated that the inclusions contained apoptotic material. The semiquantitative assessment of histochemically labeled apoptotic granules indicated that the number of lesions having moderate to large numbers of apoptotic granules (++/ ) was higher in flat adenomas with high-grade dysplasia, suggesting that the occurrence of these granules may be related to the degree of severity of the dysplastic process. A better knowledge of LB may improve our understanding of the possible relationship between apoptosis, host immune response and carcinogenesis in flat colorectal adenomas.
Collapse
|
1588
|
Tominaga I, Kaïhou M, Kimura T, Onaya M, Kashima H, Kato Y, Tamagawa K. [Cytomegalovirus fetal infection. Porencephaly with polymicrogyria in a 15-year-old boy]. Rev Neurol (Paris) 1996; 152:479-82. [PMID: 8944248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A boy, born after 41 weeks of gestation, presented with splenomegaly, microcephaly and chorioretinitis accompanied by immaturity signs. His mother was in good health but her previous pregnancy had been aborted owing to rubella. Laboratory data, including serological and virological evidence, confirmed the diagnosis of fetal cytomegalovirus infection. CT scan indicated a large cyst in the left temporal lobe and periventricular calcifications. At about 8 months of age, convulsions were noticed which were not controlled effectively by medication. There was spastic rigidity without significant psychomotor development. He died at the age of 15. Postmortem neuropathological examination revealed polymicrogyria predominant in the right cerebral hemisphere as well as a large cavity in the left temporal lobe communicating with the lateral ventricle. Widespread heterotopias and calcifications were observed notably in the periventricular white matter. No typical inclusion was found. By the method of Holzer and GFAP immunocytochemistry, no gliosis was noted in the cerebral cortex having the feature of polymicrogyria. This might support the theory that polymicrogyria is caused by neuronal migration failure.
Collapse
|
1589
|
Osoegawa K, Susukida R, Okano S, Kato Y, Lehrach H, Nizetic D, Soeda E. Potential CpG-rich islands clustering around single-minded gene in Down syndrome chromosomal region. Mamm Genome 1996; 7:461-3. [PMID: 8662217 DOI: 10.1007/s003359900134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
|
1590
|
Chung HO, Kato T, Kato Y. Molecular cloning of c-jun and c-fos cDNAs from porcine anterior pituitary and their involvement in gonadotropin-releasing hormone stimulation. Mol Cell Endocrinol 1996; 119:75-82. [PMID: 8793856 DOI: 10.1016/0303-7207(96)03798-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The presence of the typical transcription factors c-Jun, c-Fos and cAMP-responsive element (CRE)-binding protein in the porcine anterior pituitary was examined by molecular cloning and their involvement in the membrane signal cascade, especially their roles in gonadotropin-releasing hormone (GnRH) stimulation, were studied. Several cDNA clones were isolated from a porcine anterior pituitary cDNA library using cDNA probes. They were identified as porcine c-jun and c-fos by determining their nucleotide sequences, but a homologue for CREB341 which is a member of CRE-binding protein was not detected in porcine anterior pituitary. Reverse transcription-polymerase chain reaction (RT-PCR) analysis was performed to estimate the c-jun and c-fos mRNA contents in GnRH-, forskolin- (cAMP activator) and tetradecanoyl phorbol acetate- (TPA; protein kinase C activator) treated primary cultures of porcine anterior pituitary cells. Densitometric quantification demonstrated that GnRH and TPA treatment increased c-jun and c-fos mRNA levels significantly, whereas forskolin reduced the levels of both. Therefore, c-Jun and c-Fos are definitely present in porcine anterior pituitary and their mRNAs differentially involved in the signal transduction pathway mediated by two kinases. In particular, GnRH might regulate gonadotropin expression by increasing of c-jun and c-fos levels.
Collapse
|
1591
|
Fujita N, Kato Y, Naito M, Tsuruo T. A novel anti-Thy-1 (CD90) monoclonal antibody induces apoptosis in mouse malignant T-lymphoma cells in spite of inducing bcl-2 expression. Int J Cancer 1996; 66:544-50. [PMID: 8635872 DOI: 10.1002/(sici)1097-0215(19960516)66:4<544::aid-ijc20>3.0.co;2-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Mouse malignant T-lymphoma CS-21 cells can survive and proliferate in vitro when co-cultured with CA-12 stromal cells isolated from lymph nodes, but CS-21 cells undergo apoptotic cell death with DNA fragmentation when cultured alone. We immunized rats with CS-21 cells and raised monoclonal antibodies (MAbs) that recognized Thy-1 (CD90) or CD45 protein. The majority of these MAbs were able to inhibit the adhesion and apoptosis of CS-21 cells. When anti-Thy-1 MAbs were examined for their recognition site on Thy-1 glycoprotein, one of them, MCS-34, was found to recognize both Thy-1.1 and Thy-1.2. In addition, MCS-34, just like the anti-Thy-1 MAb G7, recognized the Thy-1A epitope. G7 was known to induce apoptosis in some T-cell hybridomas and in thymocytes. In CS-21 cells, however, G7 could not induce apoptosis, but MCS-34 could. Interestingly, MCS-34 enhanced the expression of bcl-2 protein, in spite of its ability to induce apoptosis. Upon examining the apoptosis-inducing mechanisms of MCS-34, we found that it promoted a sustained increase in cytoplasmic-free calcium in CS-21 cells. Calcium ionophore A23187 was also found to induce apoptosis in a dose-dependent manner. These results indicate that a sustained increase in cytoplasmic-free calcium by MCS-34 induces apoptosis in CS-21 cells in spite of bcl-2 protein expression.
Collapse
|
1592
|
Kato Y, Maruyama O, Chung HO, Tomizawa K, Kato T. Amino acids in highly conserved regions near the C-terminus of rat prolactin (PRL) play critical roles similar to those in binding of human GH to the PRL receptor. Biochem Biophys Res Commun 1996; 222:547-52. [PMID: 8670242 DOI: 10.1006/bbrc.1996.0781] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The fourth helix (helix 4) in the human growth hormone (hGH) molecule plays a role in binding to the GH receptor as well as the PRL receptor through topologically different amino acids. This study investigated the function of amino acids in the predicted helix 4 of rat prolactin (rPRL) using site-directed mutagenesis. Twenty mutants for 7 amino acid residues were expressed in COS-1 cells and their receptor binding and Nb2 proliferation activities were assayed. It was found that R174 (R at residue number 174), K179, and D181 are indispensable for PRL function, while D176, S177 and C189 are important to some extent. When these results were compared with those reported for binding of hGH to its receptors, the binding of PRL to the PRL receptor was shown to involve amino acids topologically similar to those in the binding of hGH to the PRL receptor, rather than those in the binding of hGH to the GH receptor.
Collapse
|
1593
|
Hirasawa Y, Sugimoto T, Fukuyama S, Kato Y, Takamatu H, Ohno M, Nishino S, Kato M, Maeda K, Seki J, Kita Y. Antianginal effects of FR144420, a novel slow nitric oxide-releasing agent. Eur J Pharmacol 1996; 303:55-9. [PMID: 8804911 DOI: 10.1016/0014-2999(96)00105-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The aim of this study was to compare the antianginal effects of two compounds that release nitric oxide (NO) spontaneously, i.e. (+/-)-N-[(E)-4-ethyl-3-[(Z-hydroxyimino]-5-nitro-3-hexenyl] -3-pyridinecarboxamide (FR144420) and (+/-)-(E)-ethyl-2-[(E)-hydroxyimino] -5-nitro-3-hexenamide (FK409), in two different rat models of coronary vasospasm. In the rat methacholine-induced coronary vasospasm model, FR144420 suppressed the elevation of the ST segment dose dependently and significantly at 1.0 mg/kg, i.d. 185 min after its administration. FK409 suppressed the ST elevation only 5 min after its administration at 1.0 mg/kg, i.d. FR144420 and FK409 significantly decreased mean blood pressure at all doses tested only 5 min after their intraduodenal administration, but did not change heart rate at any time. Although the suppression of the ST elevation by FK409 had the same duration as its hypotensive effect, the FR144420-induced suppression of the ST elevation lasted longer than its hypotensive effect. In the rat vasopressin-induced coronary vasospasm model, FR144420 (32 mg/kg) significantly inhibited the depression of the ST segment both 60 min and 120 min after oral administration, whereas FK409 (32 mg/kg) significantly inhibited this ST depression only 60 min after oral administration. These data suggest that FR144420 inhibits coronary vasospasm for longer than FK409 does and particularly shows more prolonged antianginal effects than hypotensive effects in the methacholine-induced coronary vasospasm model. Thus FR144420 is expected to be a useful NO releaser for investigating the in vivo actions of NO.
Collapse
|
1594
|
Chung YS, Yamashita Y, Kato Y, Nakata B, Sawada T, Sowa M. Prognostic significance of T antigen expression in patients with gastric carcinoma. Cancer 1996; 77:1768-73. [PMID: 8646672 DOI: 10.1002/(sici)1097-0142(19960501)77:9<1768::aid-cncr2>3.0.co;2-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND Thomsen-Freidenreich (T) antigen, the immediate precursor antigen of the human blood MN system, has been detected in malignant cells, but not in most normal cells in which it is cryptic but can be unmasked by desialylation. In this study, we determined the prognostic significance of T antigen in specimens with gastric carcinoma. METHODS Expression of T antigen was studied immunohistochemically in 157 gastric carcinoma tissue specimens obtained at surgery from the First Department of Surgery, Osaka City University Medical School between 1983 and 1987. RESULTS T antigen expression was detected in 72 of the tumors (45.9%). The staining pattern was inclined to change from a luminal surface type to a cytoplasmic type in accordance with decreasing degree of cell differentiation. The rate of expression of T antigen significantly increased (P < 0.05) with serosal invasion, and was significantly higher (P < 0.01) in patients with hepatic or lymph node metastasis or peritoneal dissemination than in those without such metastasis or dissemination. Furthermore, among patients with Stage III or IV disease, those with T antigen-positive tumors had a significantly poorer prognosis than those with T antigen-negative tumors. CONCLUSIONS Our findings suggest that relationships exist between expression of T antigen and depth of invasion, hepatic metastasis, lymph node metastasis, or peritoneal dissemination, and that T antigen may be a good indicator of the prognosis of patients with gastric carcinoma.
Collapse
|
1595
|
Kato Y, Ozono S, Shuin T, Miyazaki K. Slow induction of gelatinase B mRNA by acidic culture conditions in mouse metastatic melanoma cells. Cell Biol Int 1996; 20:375-7. [PMID: 8688855 DOI: 10.1006/cbir.1996.0044] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Gelatinase B has been thought to be a key enzyme for degradation of extracellular matrix in tumour invasion and metastasis. In this study, we examined the effect of acidic culture medium (pH 5.9) on the expression of gelatinase B mRNA in mouse metastatic melanoma cell line (B16-F10). Using reverse transcription-polymerase chain reaction (RT-PCR) analysis, we found that gelatinase B was induced by the acidic culture medium at 24 h, and then gradually diminished to 72 h. By gelatin zymographic analysis, gelatinase B was first detected at 24 h, continued to increase and then reached a plateau at around 48 h. These results suggest that the induction of gelatinase B secretion by acidic culture medium occurs as a result of the gene expression.
Collapse
|
1596
|
Nakakura M, Kato Y, Hayakawa E, Ito K, Kuroda T. Effect of pulse on iontophoretic delivery of desmopressin acetate in rats. Biol Pharm Bull 1996; 19:738-40. [PMID: 8741586 DOI: 10.1248/bpb.19.738] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The effect of pulse parameters (duty and frequency) in a constant direct current iontophoresis on the antidiuretic response (elevation in rat urinary osmotic pressure) of desmopressin acetate (DDAVP) was examined in diabetes insipidus rats. Although antidiuretic response was not affected by frequency, it was induced by a duty of more than 26% and prolonged with increasing duty. A positively relationship between dose and AUC, the area under the osmotic pressure-time curve, was confirmed by intravenous administration of DDAVP, and the AUC induced by the iontophoretic delivery increased with increasing duty. The voltage across rat skin required to maintain a constant current density was investigated. A higher voltage was initially applied rat skin in a higher duty. This was related the prolonged pharmacological response induced by iontophoresis.
Collapse
|
1597
|
Rubio CA, Kato Y, Hirota T, Muto T. Flat serrated adenomas of the colorectal mucosa in Japanese patients. In Vivo 1996; 10:339-43. [PMID: 8797037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
While reviewing the histological sections of 319 flat colorectal polyps at three different Hospitals in Tokyo, 7 cases of flat serrated adenomas were found. Flat serrated adenomas differ histologically from flat tubular adenomas. In the former the dysplastic cells are found initially at the lower part of the crypts of Lieberkuhn, and the epithelium of the sides of those crypts have serrated infoldings without dysplastic cells. In flat tubular adenomas, however, the dysplastic cells are initially found in the upper part of straight crypts (i.e. without epithelial infoldings). Six of the 7 serrated adenomas had low grade dysplasia (LGD) and the remaining one high grade dysplasia (HGD). Atypical mitosis were present in the dysplastic epithelium of serrated adenomas. Depending upon the topographic distribution of the dysplastic epithelium within the crypts flat serrated adenomas were divided into Type I, where the dysplastic epithelium was limited to the lower half of the serrated crypts, and Type II where the dysplastic epithelium was present even in the superficial half of the serrated crypts. Of the 7 serrated adenomas, 3 were Type I and the remaining 4 Type II lesions. The dysplastic epithelium seemed to have originated at the base of the crypts and progressed upwards, replacing the scalloped, serrated epithelium. Flat serrated adenomas appeared as benign lesions upon endoscopy (their pit pattern being identical to flat hyperplastic polyps), but in a previous survey of Swedish patients 3 of 47 flat serrated adenomas had invasive adenocarcinoma (i.e. with submucosal extension). Whether serrated adenomas evolved into invasive carcinoma in the Japanese should be assessed in a larger series of cases.
Collapse
|
1598
|
Yamauchi K, Murakami Y, Koshimura K, Nishiki M, Tanaka J, Kato Y. Involvement of pituitary adenylate cyclase-activating polypeptide in growth hormone secretion induced by serotoninergic mechanisms in the rat. Endocrinology 1996; 137:1693-7. [PMID: 8612503 DOI: 10.1210/endo.137.5.8612503] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Pituitary adenylate cyclase-activating polypeptide-38 (PACAP-38) stimulated GH secretion in superfused rat anterior pituitary cell in vitro and in conscious male rats in vivo. PACAP-38-induced GH secretion was inhibited by PACAP-(6-38), an N-terminal-deleted analog, at 100-fold concentrations of PACAP-38 both in vitro and in vivo. In contrast, a GH-releasing hormone antagonist did not affect the action of PACAP-38 to stimulate GH release in vitro. Plasma GH increase induced by i.v. injection of 5-hydroxy-L-tryptophan (1 mg/100 g BW), a precursor of serotonin, was blunted by PACAP-(6-38) (1 nmol/100 g BW, i.v.), whereas spontaneous pulsatile GH secretion in conscious male rats, which is governed by hypothalamic GH-releasing hormone and somatostatin, was not affected by repeated i.v. injection of PACAP-(6-36). These findings suggest that PACAP-(6-38) is a potent antagonist of PACAP-38 to stimulate GH secretion both in vivo and in vitro. Taken together with the facts that PACAP-38 is highly concentrated in the hypothalamus and that is released into the hypophysial portal blood, our present findings suggest that PACAP-38 might play a stimulatory role on GH secretion induced by serotoninergic mechanisms in the rat.
Collapse
|
1599
|
Kato Y, Kokubo Y, Narita Y, Kuzuhara S, Naito Y. [A case report of exercise-induced anaphylaxis]. Rinsho Shinkeigaku 1996; 36:680-2. [PMID: 8905989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We report a case of 44-year-old Japanese man who presented with exercise-induced anaphylaxis. He was admitted to our hospital with chief complaints of repeated episodes of urticaria and nausea induced by exercise. He had allergy to the radiologic contrast iodine material, but no history of atopic dermatitis. Physical and neurological examinations were unremarkable. Treadmill test induced urticaria and nausea in 10 minutes after starting the exercise and the test was discontinued. The systolic blood pressure finally fell down to 51mmHg about 17 minutes after ceasing the exercise, and it returned to normal value with hydrocortisone and noradrenalin injection. Treadmill test increased the serum histamine level, but did not increase serotonin nor IgE levels. Administration of antihistamines and avoidance of hard exercise has protected him from a new attack. We have to pay attention to exercise-induced anaphylaxis as one of the important causes of syncope.
Collapse
|
1600
|
Kuramoto H, Jobo T, Kato Y, Tateoka K, Sato R. [Hormone therapy of endometrial carcinoma]. Gan To Kagaku Ryoho 1996; 23:673-7. [PMID: 8645016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Various hormone therapies for endometrial carcinoma have been reported in the literature using progestins, tamoxifen (anti-estrogen), danazol, Gn-RH etc. The response rates of these hormone therapies are reported to be approximately 30%, which is no longer superior to other types of treatment methods. On the other hand, endometrial carcinoma is considered to be one of hormone dependent tumors. Although sex steroid hormones play an important role in the mechanism of carcinogenesis and the progression of early and well-differentiated endometrial carcinoma, most of the advanced carcinomas treated by hormone therapy have transformed into hormone independent state. It is expected that endometrial hyperplasia and well-differentiated carcinoma especially in younger patients should be effective materials for hormone therapy.
Collapse
|